According to the invention, a motion vector can be accurately and efficiently detected with regard to any type of images having a variety of characteristics. A motion vector detection unit detects a motion vector with regard to a coding target block on the basis of correlation with a candidate block within a search range. A search range storing memory stores pixel data of an original search range, and supplies, to the motion vector detection unit, pixel data of a search range in accordance with a memory address. A control unit sets the size and the position of the search range on the basis of the motion vector and the correlation evaluation value supplied from the motion vector detection unit, and generates pixel widths in the horizontal and vertical directions of the search range and an offset value corresponding to the relative position to the original search range. An address generation unit generates the memory address to be supplied to the search range storing memory on the basis of the pixel widths and the offset value of the search range generated by the control unit.